The Pats have $60mm in available cap space, and spend close to the cap every year.
Hightower has always seemed like a Belichick guy - football is important, film study, do your job, versatile, smart, tough. He is less flashy than Collins or Chandler Jones, and more dependable. I would compare Hightower more to Mayo than Collins or Jones, and I think you can argue that the Patriots overpaid Mayo.
I am not surprised that they did not franchise him.
I am not surprised that Hightower wants to test free agency.
I would not go nuts with an offer pre-free agency if I was the Patriots GM, and I would go relatively high to match a competing offer.
I think with a player with Hightower's character, I would go more years and more guaranteed. I thin Hightower is the type of player the Patriots pay - like Mankins, Mayo, Wilfork, McCourty.
I will be surprised if he is not back.